Genetic Basis of Disease Flashcards
what is a gene
basic unit of heredity
what are epigenetic changes
alterations of gene expression
what are pharmacogenomics
interactions btwn genetics and meds
what are genetics
study of inherited traits or study of genes
what are genomics
study of all genetic material
what is DNA
double stranded helical structure of nucleotides
what is central dogma
how it works
what are exons
portions of genome that encodes proteins
what are introns
portions of genome that do not encode for proteins
what are codons
set of 3 nucleotides that signal a specific amino acid
what are genetic mutations
damage or change to a gene that alters genetic code
may be inherited or occur sporadically
what is a germ cell mutation
gametes affected: may be passed to offspring
what is a somatic cell mutation
body cells
not passed to offspring
what is gene nomenclature
specific name: BRCA1
what is gene locus
chromosome #, arm, and region
what happens in transcription
DNA to mRNA
RNA polymerase uses DNA as template to form mRNA strand
spliceosomes- excise introns
mRNA leaves nucleus
what happens in translation
mRNA to protein
ribosome- mRNA transcript “read”
tRNA- one end binds to 3-nucleotide sequence on mRNA…. other end contains corresponding amino acid for the nucelotide sequence
amino acids linked by peptide bonds
what is allele inheritance
a gene that is inherited from 1 parent
what does heterozygous mean
alleles carry different traits
what does homozygous mean
alleles have idenitical triats
what does dominant trait mean
1 allele needed for expression indicated by capital letter
what does recessive trait mean
both identical alleles needed
indicated by lower case letter
what is a carrier
heterozygous for recessive trait
what is a genotype
a genetic code
what is a phenotype
physical expression of genes
what is mendelian inheritance
1 copy of a gene inherited from both parents
what are autosomal triats
1 copy of dominant allele or 2 copies of a recessive allele to express a quality
what is sex linked inheritance
x-linked inheritance
what is genetic penetrance and expressivity
ratio of ppl w/ a phenotype combined to the genotype
what are some charatcerisitcs of mitochondrial DNA
inherited from mother
can be damaged by free radicals
damage implicated in disease like diabetes, cancer and heart failure
disorders can be inherited: neurodegenerative disorders, hypertrophic cardiomyopathy
what is aneuploidy
different # of chromosomes than 46
what is translocation
1 piece of a chromosome breaking off and joining another
what is deletion
piece of chromosome is broken and lost
what are some examples of genetic assessment
pedigree (genogram)
karyotyping
polymerase chain reaction
FISH
southern blotting
what are some characterisitics of prenatal screening
women 35 yrs or older
abnormal ultrasound findings
close blood relative couple
condition w/ risk of fetal problems
unexplained or multiple miscarriages
family hx
early detection of birth defects
what are examples of prenatal genetic disorder screening
materal serum screening
chorionic villus sampling
amniocentesis
percutaneous umbilical cord blood screening
what can prenatal genetic screening identify
neural tube defects
down syndrome
chromosome abnormalities
spina bifida
cleft palate
cystic fibrosis
what are some characteristics of familial hypercholesterolemia
autosomal dominant- short arm of chromosome 19
lack of LDL receptors (elevated LDL in blood)
homozygous (more severe) and heterozygous forms
widespread atherosclerosis may develop
what are some characterisitcs of marfan’s syndrome
autosomal dominant- can result from sporatic mutation
fibrillin-1 gene mutation on chromosome 15
damage to fibrillin
heart diease- mainly aortic dilation and dissection- avg death 30-40
what are some characteristics of cystic fibrosis
autosomal recessive
defect in cystic fibrosis transmembrane conductance regulator gene
disrupts lung function (excess mucous) and pancreatic secreation (malabsorption of nutrients)
treatments- pancreatic enzyme supplements, bronchodilators, mucolytics, and nutritional supplements
what is tay-sachs disease
lysosomal storage disease
abnormal hexosaminiase A enzye (chomosome 15) leading to ganglioside accumulation in CNS
what is neimann-pick disease
lysosomal storage disease
deficiency in sphingomyelinase
lipids accumulate in brain, spleen, liver, and lymph nodes
what is gaucher disease
most common lysosomal storage disease
accumulation of glucocerebrosides in macrophages and CNS
150 gene mutations can result in this condition
what is klinefelter syndrome
XXY karyotype
lack of development of testes, gynecomastia, skeletal and heart abnomalities
decreased cognitive development
testosterone replacement needed
what is turner syndrome
X0 karyotype
may result in spontaneous abortion
short stature and infertility
lack of breast development and amenorrhea at puberty
estrogen therapy and hormone replacement
what is down syndrome
trisomy 21
most common chromosomal disordere
flat facial profile, epicanthic folds around eyes
80% have IQ of 25-50
